Prevent attribute-decorated Enums from being handled by DataContract converter
Add basic support for Enum types
Add support for IEnumerable<T> generic types
Revert "Add support for IEnumerable<T> generic types"

This reverts commit 521b529d83f83433f007335447b94c710d184b21.
Add support for IEnumerable<T> generic collections
Preliminary work towards support for some IDictionary<,> generic types